Abstract: The multiple replacement amplification technical（MDA）is a kind of the whole genome amplification（WGA）which based on strand displacement amplification. It has higher amplification efficiency rate and fidelity characteristics and so on. Although it is ued in the single cell amplification except a little defects, it has acquired great progress in the practice research and clinical application of preimplantation genetic diagnosis（PGD）. MDA has succeed in PGD when combined with standard PCR method. It makes master synchronism diagnosis of single test embryo biopsy, the single embryo cell gender and monogenic
disorder come ture. MDA has impelled rapid development of PGD technology.

Key words: Preimplantation Genetic Diagnosis, Whole genome amplification, Multiple displacement amplification